“The attack was overloading our systems with massive amounts of traffic, but it did not access any data in servers,” Erickson said.

The site, which has more than 2 million subscribers, was down for much of Tuesday and wasn’t fully operational Wednesday afternoon. Its Web team neutralized the DDoS attack and was working to fully restore services.

“This has been a very frustrating and overwhelming experience, and our teams have been fantastic, working around the clock to make it neutralized,” Erickson said.

Company officials are hoping to fully recover from the attack soon. Ancestry.com is posting updates on its Facebook and Twitter pages.

Erickson said she doesn't know where the attack came from.

“These types of attacks aren’t unique to Ancestry. We know of many other companies that have been victim to these types of attacks. It’s unfortunate that any company has to go through something like this,” she said.

The attack also impacted Ancestry.com's sister site Find a Grave, though as of Wednesday afternoon it was back up, according to its Facebook page.

Company officials said the sync and search feature in Family Tree Maker were still disabled until the site stability had been fully restored. They recommended people use the feature offline.